Coastal strand habitat is an area of beach or sand dunes that may develop along the ocean above the high tide line. The sand is loosely consolidated or unconsolidated and is moved about by ocean winds. This difficult habitat supports a unique vegetation of a few highly adapted species that are low-growing and wide-spreading and have deep roots. Much of California's coastal strand habitat has been lost to development and recreational use.

Before the arrival of Europeans, San Elijo lagoon was separated from the ocean by beach and dunes that extended across its width, from Cardiff State Beach on the north to the Cardiff Reef parking lot on the south. The strand morphology was constantly shifting, sometimes blocking the entrance to the estuary which in turn broke through in another place. This strand habitat was eliminated by the construction of the railroad and Coast Highway. However, remnant sandy areas still exist between the two transportation corridors, and these support several relict coastal strand species, some of which are rare and endangered. This area is the focus of an ongoing restoration by the Conservancy. While we will never recreate the dunes, we hope to maintain enough of the open sandy areas to support a viable coastal strand habitat.